Doh! I came here hoping for some sort of official ruling, but alas there doesn't seem to be one.
So, here are my thoughts on the issue:
The spell description says "The bone spirit’s powers are selected when the bone circle is created", but it doesn't say the *player* gets to select the powers. I think at the very least, the GM should tell the player what the powers are when cast, otherwise why mention this in the spell description? But, I'm not sure about this. Maybe the player should be able to select powers, but how?
This isn't an actual summoning, so while the summoning rules on pg. 365 might be helpful, they don't really apply. In fact, this spirit hasn't been summoned by the caster at all, it was a wandering spirit that was "invited" into the circle. Thus, the caster might not get to select powers, and the spirit isn't obligated to do anything for the caster, such as use its powers to benefit them. In fact the spell says ".. but cannot otherwise be controlled."
Since this is a first circle spell, and not the 5th circle Summon talent, it makes sense that it wouldn't be nearly as powerful or useful.
Having said that, the spell should have some use, and I think that most of the time, the spirit is at least neutral to the caster, and willing to negotiate for some assistance. Just remember that it is "not very intelligent" and probably isn't thinking too much about the long-game.
I think Telarus best described the use of this spell and the ally spirit it summons. I would be very cautious as a GM for allowing the use of something like Aid Summoner for months at a time when a 5th circle magician using the Summon talent would normally only get use of this for hours at a time. In fact, you could argue that the spirit can't use "Aid Summoner", since the caster of the spell isn't the spirit's summoner at all. This power would work if they used the Summon talent, but not by simply using the Bone Circle spell.
Slimcreeper wrote: ↑
Sun Jan 06, 2019 2:04 am
I see that now! 1 power per 2 levels. I remember reading it when I first got the book and haven't been able to find it since.
I don't remember ever reading this, so if you can find it, let me know.